Precast multistory building construction



Oct. 13, 1970 c. c. WALLACE EI'AL 3,533,204

PRECAST MULTISTORY BUILDING CONSTRUCTION Filed Dec. 5, 1968 4Sheets-Sheet 1 l/Vl/E/VTORS. Clark C. Wallace John M. Sweeney 2% M m e aTHE/R ATTOR/VE Y5 Oct. 13, 1970 c. c. WALLACE ETAL 3,533,204

PRECAST IIULTISTORY BUILDING CONSTRUCTION 4 Sheets-Sheet 2 Filed Dec. 5,1968 IN VE N 7'0 RS. Clark 6. Wallace By John M. Sweeney 4/,4; M A4444;2 4/ 14- THE If? A T TOR/V5 Y5 Oct. 13, 1970 c. c. WALLACE ETAL3,533,204

PRECAST MULTISTORY BUILDING CONSTRUCTION Filed Dec. 5, 1968 4Sheets-Sheet 5 BY I 4414mm; 4/

THE/R ATTORNEYS INVENTORS. Clark C. Wallace John M. Sweeney Oct. 13,1970 Q c, WALLACE ETAL 3,533,204

PRECAST MULTISTORY BUILDING CONSTRUCTION 4 Sheets-Sheet 4.

Filed Dec; 5, 1968 INVENTORS. Clark C. Wallace ByJo/m M. Sweeney 4/;KWQ. a. g 4% THE /R A 7'7'0RNEY5 United States Patent m 3,533,204PRECAST MULTISTORY BUILDING CONSTRUCTION Clark C. Wallace, RD. 1,Harmony, Pa. 16037, and .lltglgfiM. Sweeney, 131 Sylvania Drive,Pittsburgh, Pa.

Filed Dec. 5, 1968, Ser. No. 781,378 Int. Cl. E04h 1/04, /02

U.S. Cl. 52-236 6 Claims ABSTRACT OF THE DISCLOSURE This inventionrelates to a building construction and particularly to a constructionfor multiple story structures, such as apartment and office buildings.Precast units of predetermined dimensions are utilized in theconstruction,

which is characterized by the absence of rigid moment connections in anentire structure using the system. Surprising economies are realized inerection and materials when the building construction is employed, andthe construction has been found to be more stable, and particularly moreresistant to shear forces than heretofore achieved.

We have invented a new building construction comprising an arrangementof precast vertical wall units supporting cast horizontal floor planks.The system is applicable to the construction of buildings having atleast two floors or stories and is particularly useful for largebuildings having, for example, twelve or more stories. The constructionis unique in that in an entire building of such a size, no floor isrigidly connected to a wall supporting it in a manner so as to resist amoment or force applied normal to that wall at a height above groundlevel. Such force is resisted by Wall units running perpendicular tosuch supporting wall units. A building employing our construction isself-supporting and internally resistant to moment forces as will beshown hereinafter.

Heretofore, modular units comprising rigidly connected floor and wallmembers have substantially reduced the cost of erecting buildings havingstandardized or uniform interior plans. By joining a plurality of suchunits, large buildings have been erected in less time, and with less onsite labor, than had been possible theretofore. Yet, a substantialdrawback to use of such units in constructing a building having pluralstories has been the need to use rigid connections between the floorunits and their supporting wall units to resist horizontal forces, suchas those exerted by wind and earthquake, applied to the walls of thestories.

It is Well known that such forces can be extremely large and that theeffect of such forces increases as the distance of the point aboveground level to which the force is applied increases. For example, awind force acting on a point sixteen feet above ground (the top of asecond story wall) exerts a load substantially less than the same windforce applied to a point on a wall ninetysix feet above ground (the topof a twelve story wall). Additionally, it is well understood that theload per square foot increases as the height of the structure increases.Accordingly, it is essential in building design to provide Patented Oct.13, 1970 a construction which is sufliciently strong to resist suchforces and which is stable. In this connection, a structure using ourconstruction includes wall sections which are self-supporting duringerection; upon erection, the structure is more resistant to drift due toits internal rigidity and provides better occupant comfort than nowobtained especially at great heights. Moreover, our construction iseconomical to erect and maintain.

Prior construction techniques recognized that it is necessary totransmit horizontal forces applied to a structure from the floors of thestructure into the walls whereby they can be effectively resisted.Usually, these forces are transferred from a floor directly into a Wallsupporting such floor. Since a multiple story structure has severalfloors, it has been necessary to reinforce the base of the structure, atlarge expense of time and materials, Where the shear forces are mostsevere since they are the summation of the forces applied to the upperstories of the building. In some cases, additional wall sections havebeen installed to resist these shear forces, but, since these addedsections were non-bearing walls, they were not wholly effective andtheir use merely added significant costs to construction of thestructure.

We have invented a building construction in which every wall in astructure using it is both a load bearing wall and shear resistant wall.Alternate floors of the structure are oriented perpendicular to oneanother. Each floor is supported by wall sections other than ones towhich they are shear connected. Thus, our construction permits allhorizontal forces to be transmitted from a floor section into a wallsection other than the wall by which it is supported. In other words,all horizontal forces are resisted by means of a shear connectionbetween a floor section and a wall section which supports the floorabove. As used in this specification, it should be understood that theterms floor and ceiling are interchangeable, since the ceiling of onestory is the same as the floor of the story above.

A precast system according to our invention is illustrated in theattached drawings in which:

FIG. 1 is an isometic, cut-away view of our building construction usedin a multiple story structure;

FIG. 2 is an isometric view of a typical precast unit used as a wallunit or floor plank in our construction;

FIG. 3 is a section through a building footing showing an exterior wallsection and its connection with floor planks of two stories;

FIG. 4 shows only the first floor of the multistory structure shown inFIG. 1, before the second story walls are erected;

FIG. 5 is a partial section through a Wall showing the joint between itand adjacent floor sections;

FIG. 6 is a plan view of a building structure showing two floors of astructure constructed using our construction;

FIG. 7 is a sectional view showing an interior wall section supportingfloor planks end-to-end at a bearing point, such as identified by chaincircle VII in FIG. 6;

FIG. 8 is a cross-sectional, enlarged view of the wall corner connectionin chain circle VIII of FIG. 6;

FIG. 9 is a sectional view through a typical shear connection between avertical wall and a horizontal floor;

FIG. 10 is a plan view showing a T-joint between walls which is anenlargement of chain circle X in FIG. 6; and

FIG. 11 is a partial isometric, showing an exterior View of a structureincorporating our novel precast building construction.

Referring to FIG. 1, a four story section of a multiple story buildingincluding our invention illustrates the principles of our invention. Thebuilding section shown is supported on a concrete footing 10. Precastwall units 12 are erected vertically on the footing 10.

Although other types of precast units may be used in our invention, weprefer to use a precast unit of the typical type shown in FIG. 2. Thisunit comprises an elongated body 14 having edges 16 and ends 18. Onestandard size for such units is 4 feet wide x 8 feet long and 8 inchesthick; a 16 foot length is also standard. A plurality of symmetricallongitudinal openings 20 are formed in the body substantially parallelto the edges 16. The purpose of the openings is to reduce the totalweight of the body. Along the edges 16 of the body are longitudinalgrooves 22, which, when two bodies, such as 14 and 14a (partiallyshown), are placed with their edges 16 adjacent one another, form a keygroove 24 which may be filled with grouting or the like to retain thebodies in position edgeto-edge.

As shown in FIG. 3, each wall unit 12 is aligned with a portion offooting 10 and extends vertically above it. A metal reinforcing bar 26is embedded in footing 1t) and runs longitudinally through the wall unit12 to position it securely. A part of floor plank 28 forming the floorof a second story is shown extending perpendicularly to the wall unit 12and is secured to the unit 12 by a second reinforcing bar 30 which isbent at right angles. One end of the bar 30 is anchored in unit 12, theother end is secured to floor plank 28. A dowel 32 extends verticallyfrom unit 12 into a wall unit 34 aligned with unit 12.

The longitudinal axis of a floor plank 36 forming a portion of the floorof the third story extends parallel to the plane of the wall of whichunit 34 is a part. Floor plank 36 is perpendicularly oriented to floorplank 28 of the floor below it. A type of shear connection 38 to bedescribed in detail with reference to FIGS. 9 and 10 joins plank 36 to awall unit 34. Other types of shear connections between wall units andfloor planks are also possible, for example grouting alone can be usedwhere it is capable of transmitting the force applied to the connection.Uniformly throughout a structure using our construction, floor planks ofalternate stories are disposed perpendicular to each other.

Again referring to FIG. 1, precast building units 12 are located on thefooting 10 edge-to-edge to form a continuous wall extending from thefooting a single story in height. A floor, comprised of a plurality offloor planks 28, is lead across the top edge of wall units 12 andsupported by a similar set of wall units 12a (see FIG. 4) which extendvertically from a second footing (not shown) spaced from wall units 12 adistance substantially equal to the length of a floor plank 28. Theentire portion of the first story construction shown in FIG. 1 is betterillustrated in FIG. 4.

FIG. 4 shows the construction of a portion of a first story of amultistory building including vertical wall units 12, 12a and 12b whichsupport second floor planks 28 and 28a. Floor planks 28 and 28a arepositioned endto-end such that their adjoining ends each are supportedby substantially one half of the top edge of vertical wall unit 12a.Floor planks 28a are laid edge-to-edge across the top edges of wallunits 12a and 12b forming the first story ceiling of the building andgenerally forming two large volumes A and B.

A second story is constructed, as shown in FIG. 1, by verticallyinserting wall units 40 in longitudinal slots formed by spacing secondfloor planks 2801 from each other a distance slightly greater than thethickness of a single wall unit 40. As shown, each wall unit 40 isapproximately twice as long as the height of a single story of themultistory structure, and it extends upwardly to support the floorformed by floor planks 42 of a third story of the building. Although itis not necessary that each wall unit, such as 40, be two stories inlength, each interior supporting vertical wall unit of our buildingconstruction should extend more than a single story. In other words,although the stories of the building need not be of the same height, itis necessary that the heigth of shear resistant wall units be greaterthan a single story to permit the connection of an intermediate floor tothose wall units.

Floor planks 42 extend across the top edges of adjacent wall units 40and run perpendicular to the floor planks of the next verticallyadjacent story. The floor planks 42 extend across a series of wall units40 to rest on the top edge of a set of wall units (not shown) which runparallel to wall units 40. Thus, the spaced walls are formed of adjacentwall units running parallel to each other and perpendicular to floorplanks which they support. This is clearly shown in FIG. 6 whichcompares two floors of a building utilizing our construction. The upperportion of the drawing shows a floor 44 which runs perpendicular to thenext vertically adjacent floor 46 i.e. the one below it (illustrated inthe lower half of the drawing). By orienting adjacent fioorsperpendicular to one another, vertical and horizontal force loads aredistributed into all the Walls.

The foregoing description outlines the basic features of our invention.The most significant feature of the invention is our provision of Wallunits which extend more than a single story and the positioning of suchunits in slots formed by spacing adjacent perpendicularly positionedfloor planks forming the floor of a story above the base of such walls,such that each such vertical wall unit in the structure constitutes abearing wall.

As is well known in the art, bearing walls resist shear stressessubstantially better than do non-bearing walls. Thus, a structureutilizing our construction is comprised of all bearing walls which whenconnected to the floor units provide the structure with substantialresistance strength against forces, such as wind and earthquake forces,tending to create moments and shears apt to collapse the structurewalls.

As shown in FIG. 1, additional wall units 48 of two story length may bepositioned vertically in a longitudinal slot formed betweenperpendicularly positioned floor planks, for example, of the third storyfloor, shown at 50. Additional floors formed of floor planks 52 aresupported by wall units 48 and 54 to form a fourth story of thestructure. This construction features repetition of the method oferecting adjacent stories in that each floor runs perpendicular to thefloor above and below it and is supported by wall units which extend adistance of at least greater than a story below it. Single story wallswhere required such as wall 56, are formed by connecting a series ofprecast units to the footing or floor of adjacent stories.

As shown in FIG. 4, a corridor may be formed adjacent the volumes A andB by spacing a pair of vertical wall units 12a from each other. Acrossthe top of the corridor is a header 58 comprising an angle which isanchored to each unit 12a. After the header is positioned properly,floor planks 28b of the same or different width than planks 28 may beextended between vertical wall units 12b and the header 58 to form thecorridor ceiling.

An important aspect of our construction, shown in FIG. 5, comprises theconnections between the vertical wall units and the horizontal floorplanks which adjoin one another in various arrangements throughout abuilding embodying our system. A wall unit 60 which is ap proximatelytwo stories in length or about 16 feet long is supported on a floor (notshown) and extends through a slot 62 between two planks 64 and 66forming a part of the next highest floor of the structure. The floorplanks are attached to the wall by shear connections, which, forinterior walls. may comprise simply grouting the solid space between thefloor planks and wall unit to permit transfer of force from the planksinto the wall. Another type of shear connection which may be used oninterior walls and must be used for exterior wall sections includes anangle member as will be described in detail hereinafter with referenceto FIGS. 9 and 10.

In FIG. 5, grouting 68 is applied in the spaces between the wall unitand the floor planks to form a seal therebetween to vertically align thewall unit between the floor planks and to stabilize or make thestructure rigid to minimize drift force. In some instances, it isnecessary to align a wall unit, such as 60, by driving a wedge 70between the edge of a plank 66 and the face of a wall unit 60. Slotsformed by spaced floor planks are preferably about inches wide and awall unit, such as shown in FIG. 2, is typically 8 inches thick;therefore, approximately a one inch space remains to be filled withgrout or other suitable material, if necessary, on each side of a wallunit.

An important connection is that which is made between an interior walland the floor planks supported by that wall of the structure. Chaincircle VII in FIG. 6 identifies the position of one such connection. Asshown in FIG. 7, a pair of floor plan-ks 72 and 74 are horizontallysupported by a wall unit 76, the ends of the planks being slightlyspaced apart. A wall unit 78 forming a part of the wall above theportion of the floor shown is vertically aligned with the lower wallunit and supported by the floor planks. To maintain this alignment, adowell 80 is placed between the wall units. Metal reinforcing bars, oneof which is shown at 82, are positioned in the aligned key grooves ofthe floor planks. The entire connection is then grouted solid.

The connection at the corner of the structure between exterior walls,such as 84 and 86, and shown in the chain link circle identified as VIIIin FIG. 6, is enlarged in FIG. 8. Two perpendicularly oriented precastreinforced concrete units (of the type shown in FIG. 2) are joinedcorner to corner as, for example, at the corner of a building. Embeddedin each of the precast units is a metal anchor bar 88 having a baseplate which is flush with a face 99 of the unit. To attach the two unitstogether, an L-angle 92 is positioned between them such that the flangesof the angle mate with the base plates of the anchor bars of the precastunits. The angle is then welded or otherwise suitably attached to thebars.

A typical shear connection between an exterior wall unit and a floorplank is shown in FIG. 9. Substantially the same type of angleconstruction is used in this connection; however, the function of thisconnection is to transmit horizontal force from a fioor section 94 intoa wall section 96 joined by an angle 98. The shear connections betweenfloor planks and wall units in our construction are made between a floorplank and a wall unit other than a wall unit which supports such floorplank. In this manner, any horizontal force applied to such floor plankis transmitted to a bearing wall for effective shear resistance.

In FIG. 10, the shear connection in the chain link circle X of FIG. 6,between two wall units and a floor plank, is shown in plan view. Keygroove 100 between two adjacent precast units 102, 104 can be grouted.Such shear connection may be spaced as shown between two precast unitsalong an entire wall, the number of such connections being a function ofthe magnitude of the horizontal shear force on the structure at theparticular floor height under consideration.

The exterior of a structure employing our construction is shown in FIG.11. Viewed from a corner of the structure, the relative position of wallunits 106 forming wall 108 and wall units 110 forming wall 112 isclearly apparent. Windows 114 may be appropriately located in place ofany of the units 106 and 110. Doors 116 may be similarly located forentrances or balconies as desired. A roof 118 completes the structure.

Our building construction permits economical erection of a multiplestory structure using standard precast concrete reinforced, prestressedand non-prestressed units. Substantially dimensionally identical unitsmay be used as the floor plank and wall units. We prefer that only thoseunits used as floor planks be prestressed.

By using standardized materials as wall units and floor planks, it ispossible to design, quickly and economically,

an entire building having uniform features. As shown herebefore, byeliminating one or more units or using less than an entire unit, it ispossible to provide space for 5 doors, windows, and the like in thestructure.

More significantly, however, is our discovery that it is possible toconstruct a structure having no rigid moment connections and all loadbearing and shear resistant walls, and to obtain true design versatilitywithout sacrificing l0 stability of structure. Our new buildingconstruction, to our knowledge, meets all professional and governmentalstandards for structures of the type disclosed.

Having disclosed a preferred embodiment of our invention, it is to beunderstood that it may be otherwise embodied in the scope of theappended claims.

1. A building construction for a multiple story structure comprising:

(a) at least three vertically spaced floors;

(b) at least a first wall section vertically supported at one end by oneof the floors and the other end supporting a part of another of thefloors;

(c) at least a second wall section vertically positioned in a planeperpendicular to the plane of said first wall section; and

(d) a floor between the supporting and supported floors connected to thefirst wall section intermediate its ends so as to resist transverseforce through the intermediate floors by transmitting it to the firstwall section and bearing on an end of said second wall section on whichit is supported.

2. A building construction as set forth in claim 1 in which each wallsection in the structure is a load bearing member and is connected toand supports at least a floor forming the ceiling of a story other thanthe story having the floor on which the wall is supported.

3. A building construction as set forth in claim 1 in which each floorcomprises a plurality of precast floor planks and each wall sectioncomprises a plurality of pre cast wall units.

4. A building construction as set forth in claim 2 in which:

(a) at least two of the floor planks forming part of a floor are spacedapart from each other to form a slot having a width slightly greaterthan the thickness of a wall section adapted to be placed into the slot;

(b) a wall section extending vertically through the slot to rest on afloor therebellow; and

-(c) means for connecting one or both of the spaced apart floor planksto said wall section.

5. A building construction for a multiple story structure comprising:

(a) at least three vertically spaced floors each of which floorscomprises a plurality of floor planks;

(b) at least a wall section comprising a plurality of precast wall unitsvertically supported at one end by one of the floors and the other endsupporting a part of another of the floors;

(c) a floor comprising a plurality of floor planks between thesupporting and supported floors and con nected to the wall sectionintermediate its ends so as to resist transverse force through theintermediate floor by transmitting it to the wall section; and

(d) the longitudinal axis of each floor plank forming (b) at least awall section vertically supported at one end by one of the floors andthe other end supporting a part of another of the floors;

(0) a floor between the supporting and supported floors and connected tothe Wall section intermediate its ends so as to resist transverse forcethrough the intermediate floor by transmitting it to the wall section;

(d) each of the floors being formed of floor planks positionededge-to-edge;

(e) each of the walls being formed by wall units located edge-to-edge;

(f) alternate floors of the structure having their floor planks orientedsuch that the length of the planks in one of the floors extendssubstantially perpendicular to the length of the planks in the other ofthe alternate floors; and

(g) each Wall section is supported by a floor in which the longitudinalaxes of the floor planks forming the floor are perpendicular to theplane of the wall section.

References Cited UNITED STATES PATENTS OTHER REFERENCES German printedapplication 1,059,170, June 11, 1959, Dieg.

JOHN E. MURTAGH, Primary Examiner US. Cl. X.R.

